"This call for a watershed ignores the academic evidence and risks overlooking the real causes of childhood obesity", said Sue Eustace, its director of public affairs.

Dr Cass, who represents 11,500 children's health professionals on behalf of the RCPCH, also claimed the Coalition should introduce taxes on soft drinks with high levels of sugar.

Earlier this year, experts backed a so-called "fat tax", suggesting it could help reduce the number of deaths from heart attacks and strokes by half.

Professor Simon Capewell, from Liverpool University and co-author of the paper published by the European Association for Cardiovascular Prevention and Rehabilitation, said: "Much of the nanny state is manipulated by industry which leads to the nanny state generating very cheap junk food through subsidies at Common Agricultural Policy level, and an environment with advertising and marketing seducing us to buy junk food and sweet drinks.

"In this case the nanny state is malignant rather than benign and we’re looking to government to redress the balance.”